This invention claims the benefit of Japanese Patent Application No. HEI 2000-097012, filed on Mar. 31, 2000, which is hereby incorporated by reference.
1. Field of the Invention
The invention relates to a vehicle lamp for use in the illumination of a headlamp, etc., and more particularly relates to a vehicle lamp forming a light distribution characteristic in a multi-reflex manner using an ellipse group reflector and a parabolic group reflector. The vehicle lamp can have relatively small width and depth in a front view, and is particularly suited for being in disposed along a side comer of a vehicle, rather than the front end.
2. Description of the Related Art
In accordance with recent vehicle design trends which pursue improvement of energy consumption efficiency by decreasing air resistance while traveling, a vehicle headlamp is often required to have a wedge-like shape in side view with a front end that is lower than the rear end, and/or to have a substantially elliptic shape in front view with front and rear ends that are narrowed. FIG. 5 shows the positioning of automobile headlamps 80 or 90 disposed in an automobile body 70 made in accordance with current fashionable design. In this design automobile headlights 80 and 90 are assigned to relatively larger spaces at right and left sides rather than right and left front ends of the automobile body 70.
Conventional automobile headlights cannot include the above-mentioned current design trend for automobile bodies while also satisfying light distribution pattern requirements.
FIG. 6 shows a conventional automobile headlamp 90 that has parabolic group reflecting surfaces 91a and 91b, e.g., rotated parabolic surfaces. Since the width of a front lens 92 as viewed from the front is small, the automobile headlamp 90 is required to have a larger reflecting area at its sides to compensate for the reduced width, and to obtain a predetermined light amount as required by regulation. In the automobile headlamp 90, the reflecting surface 91a, as shown in dotted lines, is located in a backward orientation. Accordingly, the reflecting surface 91a provides insufficient space for the wheel tire housing. If the reflecting surface 91b, which is located forward of reflecting surface 91a, is used for solving the space incompatibility problem with wheel tire housing, the total light amount produced by the automobile headlamp 90 decreases as the total area of reflecting surface of the automobile headlamp 90 decreases Furthermore, a blind/shade 93 must be used to avoid making the back surface of the reflecting surface 91b visible through the front lens 92, which deteriorates the aesthetic appearance of the automobile headlamp 90.
FIG. 7 shows another conventional automobile headlamp 80 that has an ellipse group reflecting surface 81, e.g., a rotated elliptic surface. Automobile headlamps having rotated elliptic group reflecting surfaces tend to have a relatively large depth, and therefore competition for space with tire wheel housing is significant. Accordingly, the ellipse group reflecting surface 81 must be located forward, and a blind/shade 83 is required to conceal a projection lens 82 from being visible through the front lens of the automobile headlamp 80, which would deteriorate the aesthetic appearance of the automobile headlamp 80.
In order to resolve the aforementioned problems in the related art, the present invention can include a tube-like lamp element having a multi-reflex optical system with at least two ellipse group reflecting surfaces that are combined to form a multi-reflex optical system with an aperture from which light rays are guided outside of the tube-like lamp element. A light-source can be located on a common first focus of the at least two ellipse group reflecting surfaces. One of the at least two ellipse group reflecting surfaces can have a longer focal distance than other ellipse group reflecting surface(s), and can have a different longitudinal direction than other ellipse group reflecting surface(s). In addition, a second one of the at least two ellipse group reflecting surfaces can have an inner reflecting surface portion for directing light rays, which were previously traveling towards a second focus of a first one of the ellipse group reflecting surfaces, towards a second focus of the second of the ellipse group reflecting surface(s); thereby forming a complex second focus of the tube-like lamp. The aperture formed by the ellipse group reflecting surfaces is preferably located around the complex second focus.
A lamp according to the invention can include two or more tube-like lamp elements having a multi-reflex optical system with a common light source located on the first focus of each tube-like lamp element.
The invention can also include a vehicle lamp that has a multi-reflex optical system which includes a parabolic group surface reflector and a front lens. The lamp can include at least one tube-like lamp element that is configured as described above, such that light rays emitted from the aperture are directed to the parabolic group surface reflector. One of the aperture, parabolic group surface reflector, or front lens can be configured to give predetermined forms to the light distribution patterns of the vehicle lamp.